The temperature dependence cf the pbotoiuminescer.ee in GaPiN has been investigated in the range of 20K-120K. The following experimental phenomena show that there would be exciton transfer between different luminescent centres in GaP:N. (1) With the increase cf temperature from 20K to 60K

the emission intensity of higher energy band (18760cm

-1

-18280cm

-1

) decreases rapidly

while that of lower energy band (17640cm

-1

-17050cm

-1

) increases. However

the total intensity of all luminescent lines decreases slowly when the temperature increases from 20K to 60K

and decreases rapidly when T exceeds 60K. (2) As the temperature is raised from 20K to 60K

for the deeper binding centres (e.g. NN

1

NN

3

) the emission intensity increases appreciably

(3) The NN

1

line and its phonon sidebands have been observed under A line exciting. This selective excitation experiment shows that at 77K there is exciton transfer from the isolated N to the NN

1

pair.